Process and apparatus for treating process streams from a system for separating constituents from contaminated material

ABSTRACT

A process and apparatus for recovering and treating hazardous and non-hazardous components from process streams generated from a continuous system for selectively separating organic and inorganic constituents from contaminated material. The contaminated material is heated in a dryer to a first temperature sufficient to volatilize water and lower boiling point constituents contained in the material, thereby producing a dried solid material and a first gas containing water vapor and volatilized lower boiling point constituents. The first gas is separated from the dried solid material. The lower boiling point constituents are recovered from the first gas. The dried solid material is heated in a desorber to a second temperature sufficient to volatilize higher boiling point constituents contained in the dried material, thereby producing a substantially decontaminated solid material and a second gas containing volatilized higher boiling point constituents. The second gas is separated from the substantially contaminated solid material, and the higher boiling point constituents are recovered from the second gas.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a process and apparatus for removing,recovering and treating hazardous and non-hazardous components fromprocess streams generated from a continuous system for separatingorganic and inorganic constituents from contaminated material. Moreparticularly, this invention relates to a thermal desorption/recoveryprocess designed to remove and recover constituents generated fromprocessing a solid or sludge feed, using thermal, condensation, solventstripping, filtration and gravity separation techniques.

2. Description of the Related Art

A need has arisen to decontaminate inert materials such as soil, sludge,biological and other waste materials contaminated with chemicalcompounds. In particular, it is necessary to decontaminate wasteproducts and recover the resources contained in the waste from earlymanufactured gas plant (MGP) sites, for example. Also, a need has arisento recover and treat hazardous and non-hazardous components from processstreams generated as a result of manufacturing processes, especially fora process that is flexible and amenable to be used for either discardedwaste or in-stream recovery for return to a manufacturing process.

Historically, at the turn of the century, in operating manufactured gasplants, coal was heated to drive off organic gases, which were used forheating and lighting. The gases were sent to very large receiverbuildings, typically 100 to 200 feet across, and generally made ofconcrete or some other cementitious material. The gases were cooled inthese receiver buildings. However, these gases contained heavy tarswhich were separated by cooling and gravity. These tars were separatedout from the gases and would build up on the bare ground floors in thereceiver buildings. Thus, one to twenty or more feet of soil would becontaminated with these tars. The surrounding ground would likewise becontaminated. This also resulted in pollution of nearby ground water.Accordingly, a need has arisen to decontaminate such soil.

In the past, such contaminated soil or material would be sent to adesignated landfill. However, such disposal merely relocates thecontaminated soil.

Several attempts have been made to treat such contaminated material. Forexample, incineration has become a generally accepted means fordestroying organic contaminants in such contaminated material. Suchincineration may involve collecting, packaging, and transporting a largemass of contaminated material to a licensed incineration facility,heating the large mass of inert solids to very high incinerationtemperatures to decompose the proportionately small amount of targetcontaminants and packaging and returning the materials back to thetreatment site from where they were removed, or disposed of in a securelandfill. Accordingly, such incineration has drawbacks.

U.S. Pat. No. 5,086,717 (McCrossan) discusses the removal of volatileorganic chemicals (VOCs) from soil contaminated with gasoline, dieselfuel and the like. The soil is heated in a burner-heated drum tosubstantially vaporize the VOC's . The vaporized VOC's are sent to ascrubber to be absorbed into the scrubber water, along with any airbornesoil particulates. The VOC and particulate-laden water is then sent to asettling basin to remove the particulates. Particulate-free VOC-ladenwater is removed from the basin to an air stripper where the VOC's arevaporized. The vaporized VOC's are sent back to the drum burner.

U.S. Pat. No. 5,188,041 (Noland, et al.) discusses removing VOC's fromsoil and waste materials. The contaminated material is introduced to ahopper, which is sealed from the atmosphere to prevent fugitiveemissions of the contaminants. The material is conveyed under sealedconditions into a heated vapor stripping conveyor to strip moisture andcontaminants. Non-oxidizing gases are streamed at a controlledtemperature over the material to carry the contaminants and moistureaway from the material. The flow rate and temperature of the gases aremaintained to prevent undue surface drying of the material as it passesthrough the conveyor.

U.S. Pat. No. 5,150,175 (Des Ormeaux) discusses removing and recoveringconstituents from a waste stream at temperatures higher than the boilingpoint of the constituents, and in particular, a process for thetreatment of hazardous waste in an inert atmosphere. The waste is heatedand moved at a specified retention time, through a heat zone. Componentsare separated and are released in a gaseous state, either from a liquidor a solid within the waste stream. The gaseous components aretransferred through a flow of an inert medium, such as nitrogen gas, toinhibit combustion of the components or to prevent the combination ofoxidation, or oxygen being used as a catalyst to form even morehazardous compounds. The gaseous components then are released in adistilled state, which is then mixed with the waste, or in emulsion withthe waste stream. This patent also discusses "sweeping" the wastematerial contained in the heating chamber with an inert or carbondioxide gas.

Some attempts have been made to separate contaminants from soil orsludges without incineration. For example, U.S. Pat. No. 4,977,839(Fochtman, et al.) discusses separating chemical contaminants such asVOCs and polychlorinated biphenyls (PCB's) from soils or sludges. Thecontaminated materials are volatilized below incineration temperature,with continuous removal of evolved vapors, long enough to separate thecontaminants. The vapors are catalytically oxidized to destroy thevolatilized chemical compounds.

U.S. Pat. No. 5,103,578 (Rickard) relates to the removal of volatileorganic compounds such as PCB's from soils, without incineration. Thecontaminated soil is introduced in batch into a vessel and heated to atemperature between 300° F. to 600° F., preferably in the absence of aninert gas. The vessel is subjected to a vacuum to cause the contaminantto flash to a contaminant vapor, which is condensed to a disposableliquid.

However, none of these patents teaches or suggests a process andapparatus for removing, recovering and treating hazardous andnon-hazardous components from process streams generated from acontinuous system for separating organic and inorganic constituents fromcontaminated material, as in the present invention.

SUMMARY OF THE INVENTION

The present invention provides a process and apparatus for removing,recovering and treating hazardous and non-hazardous components fromprocess streams generated from a continuous system for separatingorganic and inorganic constituents from contaminated material.

Generally speaking, the present invention provides a thermaldesorption/recovery (TD/R) process and apparatus designed to remove andrecover constituents generated from processing a solid or sludge feed,using thermal, condensation, solvent stripping, filtration and gravityseparation techniques. To recover a usable product, for example, onethat can be used by refineries, it is necessary to eliminate water fromthe contaminated material. It is known that some conventional systemsresult in a finely dispersed emulsion of water and oil, which isdifficult to break down. The present invention overcomes such drawbacksof conventional systems by effectively separating water from thecontaminated material.

The TD/R process and apparatus of the present invention thermally driesand desorbs water and organics from a feed stream of contaminatedmaterial in a dryer such as an indirectly heated screw dryer, which isclose coupled to a desorber such as an indirectly heated rotarydesorber, into separate gas streams. The feed stream is moved throughthe heated units at a particular retention time, depending on the feedstream characteristics, increasing the temperature of the stream, thusvaporizing the water and organics. The water and those organic andinorganic compounds which boil at or below the boiling point of waterare volatilized into a gaseous state in the heated screw dryer, thusgenerating a water laden gas stream from the dryer. The waste materialin the screw dryer is indirectly heated by, for example, hot oil fed tothe screw from a hot oil system. The higher boiling organic andinorganic compounds are volatilized into a gaseous state in the rotarydesorber, thus generating an organics laden gas stream from thedesorber. This stream may also include some residual inorganics. Thegaseous compounds are then transferred to separate recovery systems, ifdesired, through the flow of a sweep gas, such as a low oxygen contentflue gas or nitrogen, to suppress or inhibit combustion of thevolatilized organics.

The water laden gas stream from the dryer is transferred to a quench andcondensing system to remove the majority of the particulate, water andother gaseous components as a cooled liquid. This liquid is thensubjected to a gravity separation step to recover the low boiling pointorganic compounds and treat, as necessary, throughfiltration/absorption, the condensed water for reuse in the process ordischarge.

The organics laden stream generated in the desorber is transferred to ahot oil quench to remove particulates and condition the gas forintroduction to an absorber stripping tower. The stripping tower removesthe majority of the organics through temperature reduction andabsorption by recirculating the cooled liquid stream and, whennecessary, adding an appropriate solvent to the recirculated liquid tohelp strip the organics from the gas stream. The particulates areremoved from the liquid stream by filtration and gravity settling andthe solids are recycled to the feed stream. The stripped gas stream isthen transferred to a condenser which further reduces the gas streamtemperature and condenses most of the remaining organics. The condensedliquid is then sent to a gravity separation system to remove anyresidual water before being sent to storage.

The cooled gas streams from both the dryer and desorber can then becombined and transferred via a vent gas blower to the natural gas firedburners of the rotary desorber where any residual organics are destroyedin the burner flames. The vent gas blower provides the system draft tocontain any fugitive emissions and provide the gas motive force to pullthe gas streams through the process. The vent gas system has a burnerbypass system in the event of burner flame failure so that the systemdraft is maintained. The bypass is diverted through a carbon adsorber toassure that no contaminates are emitted to the atmosphere.Alternatively, the vent gas stream may be primarily directed to thecarbon adsorbers when it is inappropriate, due to the application, tosend the stream to the burners.

The flue gas exiting from the desorber burner chamber provides lowoxygen content sweep gas to the dryer and desorber with the remainder ofthe flue gas transferred to the hot oil system heater to recover theenergy before being exhausted through the stack to the atmosphere.Alternatively, exhaust gas from the hot oil heater may be combined withthe exhaust gas from the desorber burners to provide the dryer anddesorber sweep gas. Still further, the flue gas may go directly to thehot oil system heater and then through a nitrogen vaporizer whichvaporizes liquid nitrogen to provide an inert sweep gas to the dryer anddesorber, if required by the application.

The solids discharged from the rotary desorber are transferred via aninclined cooling screw, which provides a discharge air seal, to amoisturizer mixer where the solids are remoisturized to eliminatedusting, using the treated water condensed from the processed gasstreams.

Accordingly, the present invention is directed to a process andapparatus for removing, recovering and treating hazardous andnon-hazardous components from process streams generated from acontinuous system for selectively separating organic and inorganicconstituents from contaminated material. The contaminated material isheated in a dryer to a first temperature sufficient to volatilize waterand lower boiling point constituents contained in the material, therebyproducing a dried solid material and a first gas containing water vaporand volatilized lower boiling point constituents. The first gas isseparated from the dried solid material. The lower boiling pointconstituents are recovered from the first gas. The dried solid materialis heated in a desorber to a second temperature sufficient to volatilizehigher boiling point constituents contained in the dried material,thereby producing a substantially decontaminated solid material and asecond gas containing volatilized higher boiling point constituents. Thesecond gas is separated from the substantially contaminated solidmaterial, and the higher boiling point constituents are recovered fromthe second gas.

In a first aspect, the dryer comprises an indirect heated screw dryerhaving a screw for conveying material, while the first gas is exhaustedfrom the dryer and processed in a water spray quench condenserarrangement and an oil/water separator to recover the lower boilingpoint contaminants from the first gas. In another aspect, the desorbercomprises an indirect fired rotary calciner or pyrolizer desorber. Thesecond gas is exhausted from the desorber and processed in an oil sprayquench and an absorber to recover the higher boiling point contaminantsfrom the second gas.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a process and apparatus useful forgenerating process streams from a continuous system for selectivelyseparating organic and inorganic contaminants from contaminated solidmaterial, using (1) an indirect heated hot oil screw dryer coupled withan indirect fired rotary calciner desorber and (2) air and combustionexhaust gas used as a sweep gas.

FIG. 2 schematically illustrates a process and apparatus substantiallysimilar to those shown in FIG. 1, but using nitrogen in the sweep gas.

FIG. 3 schematically illustrates a process and apparatus useful forrecovering and treating hazardous and non-hazardous components from aprocess stream generated from the indirect heated hot oil screw dryershown in FIG. 1 or FIG. 2.

FIG. 4 schematically illustrates a process and apparatus useful forrecovering and treating hazardous and non-hazardous components from aprocess stream generated from the indirect fired rotary calcinerdesorber shown in FIG. 1 or FIG. 2.

Like reference numerals have been used for like or correspondingelements throughout the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In general, the waste material to be treated according to the presentinvention may be any material containing organic and inorganiccompounds. Typically, the waste material is waste product frommanufactured gas plants, biological solids or sludges containing organicand inorganic compounds, and even toxic organics, such as sewagesludges, pyrotechnics, dyes, phenols, polychlorinated biphenyls,polyaromatic hydrocarbons, etc. Additionally, materials containingmunicipal or industrial wastes, coal, etc. may be treated according tothe present invention. The particular organic compounds which arecontained in the waste material, and their concentration, is ofimportance only in regard to the rate of reaction and the maximumtemperatures achieved by the desorption process. In other words, anyorganic compound in any concentration can be desorbed according to thepresent invention as long as oxygen is limited and the rate of reactionand maximum temperature can be controlled. In addition, when the processof the present invention is operated in the absence of oxygen or withless than the stoichiometric amount of oxygen (e.g., to separate theorganic and inorganic components of the waste stream as describedbelow), the concentration of the waste material is less critical as longas the slurry or other form of waste material is pumpable, flowable orotherwise movable.

The residence time of the reactants in the reaction zones is dependenton several factors, including the temperature, the size of the reactors,the flow rates of materials into and through the reaction zones, etc.

In one aspect, and by way of example only, the present invention hasbeen designed to process waste material containing on the average 74%solids, 20% water and 6% organics. With these criteria, the presentinvention is sized to process approximately 52,000 pounds per hour ofwaste material. However, one having ordinary skill in the art wouldrecognize that the moisture and organics content, materialcharacteristics and the process temperatures of the waste material arethe controlling factors. For example, the system can be used to processup to about 70,000 pounds per hour of waste material having a moisturecontent on the order of 10%. The present invention also can be utilizedto process approximately 10,000 pounds per hour of waste material havinga moisture content on the order of 75% or to process as low as about5000 pounds per hour with waste material having a moisture content onthe order of 90%. At these rates, the material can be processed in aperiod between thirty minutes and two hours. Thus, the present inventionis not limited to the particular process criteria such as temperature,solids content and flow rates discussed herein. Rather, many variationsare contemplated within the concepts of the present invention.

FIG. 1 schematically illustrates a process and apparatus useful forgenerating process streams in exhaust gas lines 50 and 70 from acontinuous system for selectively separating organic and inorganiccontaminants from contaminated material, using, in the preferredembodiment, (1) an indirect heated hot oil screw dryer 40 coupled withan indirect fired rotary calciner or pyrolizer desorber 60 and (2) airand combustion exhaust gas (or nitrogen in the FIG. 2 embodiment) in thesweep gas fed in through lines 46, 66 and 68, as will be discussed inmore detail below.

Waste material or process feed is fed into the system through materialfeed 10. Material feed 10 sends material to a feed screen 14 throughfeed line 12. Feed screen 14 separates the material feed 10 intooversized and undersized particles. Oversized particles, on the order oftwo to four inches or greater, are withdrawn from feed screen 14 throughoversized particles feed line 16 and are sent to a feed shredder 18.Shredded particles from feed shredder 18 are fed through feed line 20back into the feed screen 14 together with material feed 10 fed throughfeed line 12.

Material sized to approximately two to four inches or less is withdrawnfrom feed screen 14 through sized material outlet 22. This sizedmaterial is fed to a movable radial stacker 24. Radial stacker 24functions as a conveyor to distribute the material in a fairly uniformmanner across the stock pile 26, which becomes a blend due to thedistribution performed by radial stacker 24.

A front end loader or other moving device 28 feeds material from feedstock pile 26 into live bottom hopper 30. Live bottom hopper 30 is amaterial feeder for feeding material to conveyor 32. Live bottom hopper30 provides an initial air plug to the system, and has on the order offour screws in its bottom for conveying material to conveyor 32.

Conveyor 32 comprises an enclosed inclined feed conveyor. Enclosedinclined feed conveyor 32 assists in the continuous process. A belt typeconveyor is preferred in this embodiment, as opposed to a bucket typeconveyor, because the waste material can be very sticky and tends toagglomerate. Enclosed inclined feed conveyor 32 feeds waste material toinclined feed chute 34. Of course, inclined feed chute 34 also could bevertical, if desired.

Feed chute 34 includes a weigh belt 35 that determines the process feedrate, which is, for example, on the order of 52,000 pounds per hour ofwaste material given the solids and liquids content discussed above.Again, however, the present invention is not limited to this feed rate.Feed chute 34 also includes a plurality of V-gates 36, which provide amechanical seal between the discharge of the weigh belt 35 and the feedto the next station. If used, one of the V-gates 36 is always closed inorder to prevent excess air infiltration and minimize the possibility offlashback. However, one having ordinary skill in the art recognizes thatthe V-gates 36 may not even be necessary in some applications, forexample, if the organics content of the waste material is very low.

Waste material is fed from V-gates 36 into screw dryer 40. In thepreferred embodiment, screw dryer 40 is an indirect heated hot oil screwdryer having two sets of four 24 inch inner diameter by 24 feet longscrews. This dryer is available from Denver Sala under the tradename ofHolo-flites® or from Christian Engineering, for example. In this system,hot oil flows through heated screw 42 of the dryer, with waste materialreceiving heat from the screw and being maintained on the outside of thescrew. Drive motor 44, which can be hydraulic or electric, drives heatedscrew 42. Heated screw 42 receives hot oil from feed line 47 anddischarges hot oil through discharge line 49 of hot oil system 140,which will be discussed in more detail below. Although a hot oil systemis discussed herein, one having ordinary skill in the art understandsthat other fluids, such as water or steam could be used to heat orprovide the heat-transfer medium for the material in dryer 40, dependingon the temperatures required.

Feed line 47 supplies hot oil to heated screw 42 at a temperature ofapproximately 650° F. Discharge line 49 returns hot oil to the hot oilsystem 140 at a temperature of approximately 300 to 600° F. Hot oilscrew dryer 40 also includes a pressure indicating controller 48 thatmaintains a slight vacuum in the screw dryer 40.

Waste material is typically fed in at ambient temperature and is heatedto a process temperature of approximately 200° F. to 350° F. at theoutlet end of the screw dryer 40. By way of example, screw dryer 40 hasa volume on the order of 800 ft³ with about 245 ft³ being solids andabout 545 ft³ being vapor, given the conditions discussed above.Depending on the moisture content of the waste material, the gases abovethe waste material can be just above the boiling point of water, on theorder of 212 to 220° F. As used herein, these gases are termed "lowerboiling point gases."

Hot oil screw dryer 40 also includes a sweep gas inlet 46, whichreceives flue gas from the natural gas or other fired burners 64 of therotary calciner desorber 60, as will be discussed in more detail below.Sweep gas inlet 46 provides flue gas at about 1000° F. to 1500° F. onthe order of 444 pounds per hour (100 scfm), as necessary. One havingordinary skill in the art recognizes that no sweep gas is necessary ifthe waste material has a low organics content. Therefore, our system canbe operated equally well, depending on the material characteristics,without the sweep gas system. When used, sweep gas in sweep gas inlet 46assists in exhausting gases from screw dryer 40 and in maintaining apartial pressure condition conducive to the drying of the material.Alternatively, the sweep gas can be pulled from the exit of the hot oilheater to provide a lower temperature (on the order of 500° F. to 800°F.) sweep gas when conditions warrant. This is shown by line 181 inFIG. 1. Line 181 has an appropriate control damper (not shown) for flowcontrol.

Exhaust gas is withdrawn from screw dryer 40 through exhaust gas line50. This exhaust gas contains primarily water, as well as lower boilingpoint organics--those that boil off at less than about 250° F. By way ofexample, these lower boiling point organics may include lower boilingpoint VOCs, such as benzene, toluene and acetone. The exhaust gases inexhaust gas line 50 have a flow rate on the order of about 11,450 poundsper hour, and will be discussed in more detail below with respect toFIG. 3.

Hot oil screw dryer 40 includes a soil discharge breeching 52 forfeeding dried waste material into, in the preferred embodiment, indirectfired rotary calciner or pyrolizer desorber 60 by way of transfer feedscrew 62. Feed screw 62 feeds heated discharge solids at about 41,600pounds per hour into desorber 60. Of course, this feed screw 62 alsocould be a chute or other transfer mechanism.

Desorber 60 receives inlet solids from hot oil screw dryer 40 atapproximately 250° F. Desorber 60 has approximately an 8.83 feet innerdiameter and is about 72 feet long, and is available from ABB Raymond orAllis Mineral Systems, for example. Other types of heaters capable ofgenerating the operating temperatures discussed herein can be utilized.By way of example, desorber 60 has a volume on the order of 5,400 ft³with about 4,850 ft³ being vapor and about 550 ft³ being solids, giventhe conditions discussed above. In this embodiment, desorber 60 isheated by a bank of burners 64 (approximately 24 in this embodiment)running the heated length of the desorber 62. In this embodiment, it ispreferred to suplly the burners 64 with natural gas from fuel feed 63.However, one having ordinary skill in the art recognizes that otherfuels, such as propane or fuel oil can be used. Also supplied to theburners 64 is ambient air supplied from combustion air blower 65 throughfeed line 67. Feed line 67 feeds inlet combustion air at a flow rate ofabout 41,150 pounds per hour to a distribution air header (not shown)for feeding combustion air to each burner. Desorber 60 is maintained ata temperature on the order of 800° F. to 1200° F. Depending on thematerials of construction, the outer shell temperature of desorber 60may reach 1200° F. to 2000° F. Desorber 60 also includes sweep gas inlet66 for receiving exhaust gases from burners 64 if desired. If sweep gasis utilized, we prefer to feed the sweep gas co-currently with the driedmaterial, in desorber 60. We have found that this can significantlyenhance operation with higher boiling point compounds. Burner exhaustgas is provided to sweep gas inlet 66 at a range of 500° F. to 1500° F.on the order of 0 to 2500 pounds per hour (0 to 500 scfm), depending onthe organics content and type of waste material being processed. Alsoprovided is a seal gas inlet 68 for feeding sweep gas to the sealsprovided around the end of the furnace. Seal gas inlet 68 provides up to100 scfm of exhaust gas at about 750° F.

Exhaust gas is discharged from desorber 60 through exhaust gas line 70.Exhaust gas being exhausted through exhaust gas line 70 has a flow rateof about 7775 pounds per hour and is on the order of 800° F. to 1200° F.This exhaust gas includes sweep gas and organics that boil off atgreater than 200° F. to 350° F. By way of example, such gases mayinclude asphaltenes, pyridines, pyrenes, PCBs, polyaromatichydrocarbons, pentachlorophenols and the like. Exhaust gas discharged inexhaust gas line 70 will be discussed in more detail below with respectto FIG. 4.

Desorber 60 includes an inclined discharge outlet screw 72 fordischarging the processed material at about 800° F. to 1200° F. from thecalciner desorber 60. Discharge outlet screw 72 also provides an airseal to the desorber 60. Drive motor 74 drives outlet screw 72. Ofcourse, other mechanisms could be used to effect an air seal and totransport solids, such as a rotary or double dump valve in concert witha pan conveyor, for example.

Material discharged from outlet screw 72 will effectively be drymaterial. Accordingly, this dry material is fed to a dry soilmoisturizer 76 that is fed with cooling water 80 controlled by controlvalve 82 to prevent dusting. Cooling water inlet 80 may originate fromtreated water system 390 discussed below with respect to FIG. 3. Drysoil moisturizer 76 also includes a steam vent 78 to atmosphere toaccommodate material in the dry soil moisturizer, which may be flashedinto steam. Steam vent 78 includes a plurality of tortuous paths toseparate particles. If necessary, cooling water inlet 80 can include afresh water inlet (not shown).

Moisturized soil from dry soil moisturizer 76 is fed through moisturizedsoil discharge 86 using drive motor 84 to a treated soil transfer beltconveyor 88 being driven by drive motor 90. Treated soil transfer beltconveyor 88 may be any suitable transfer conveyor, such as a flat belt,for transferring material to holding bins. Treated soil transfer beltconveyor 88 includes discharge chutes 92 for sending material to storagebins to be held for confirmatory testing. This material is fed totreated soil load out belt conveyor 94 driven by drive motor 96 forloading the material into a truck or load off bin for transport to theoriginal site or another appropriate location.

Vent gas 100 supplied from a condenser discussed below with respect toFIG. 3 feeds treated exhaust gas from hot oil screw dryer 40 at atemperature of approximately 50° F. to 160° F. through vent gas blower102 and inlet lines 104 and 106 controlled by control valve 108 intodistribution headers in natural gas fired burners 64. If desired, someor all of this vent gas 100 can be fed through inlet line 110 controlledby control valve 112 into carbon adsorbers 114. Although one carbonadsorber 114 is shown, typically three 20,000 to 40,000 pound carbonunits are used. Such carbon adsorbers are available from Calgon, NorthAmerican Aqua and other suppliers. One adsorber will be running untilbeing switched over to a second, with the third being a back-up. Carbonadsorbers 114 utilize supported granular carbon with a gas distributionchamber at the bottom where the exhaust gas is fed in from inlet line110. Exhaust gas is released from carbon adsorbers 114 through exhaustgas line 116 at a temperature of approximately 100° F. As is customaryin the industry, sample line 118 feeds exhaust gases to continuousemissions monitoring system 120. Continuous emissions monitoring system120 also can receive exhaust gases from stack 160, as will be discussedin more detail below, through sample line 122.

As discussed above, hot oil system 140 provides hot oil to the hot oilscrew dryer 40 through feed line 47, while hot oil is returned to hotoil system 140 through discharge line 49. Thus, this is a closed oilloop, which has a flow rate of approximately 100 to 1000 gpm. Hot oilsystem 140 heats the oil to approximately 650° F. Hot oil system 140 isavailable from First Thermal System or others, and uses thermal fluidavailable from Dow Chemical or Monsanto. In this embodiment, hot oilsystem 140 is heated by natural gas supplied from feed line 144.However, fuel oil, propane or equivalent fuel could be used. Combustionair is provided by combustion air blower 142 through combustion airinlet 143. Exhaust gases exit hot oil system 140 through flue gas outlet146 at a temperature of approximately 750° F. This embodiment alsoincludes the capability to heat the oil using the desorber 60 burnerexhaust gases in line 170, thus greatly increasing the overall energyefficiency of the process.

Burner exhaust line 178 withdraws exhaust gases from burners 64 at atemperature of approximately 1600° F. to 2400° F. Air inlet 174 iscontrolled by temperature indicating controller 176 to feed ambient airinto the burner exhaust in exhaust line 172. Exhaust gas line 172 feedsexhaust gas to hot oil system 140 through inlet 170 or to stack 160through burner exhaust bypass line 152. Exhaust lines 170 and 152 arecontrolled by dampers 171 and 173, respectively.

If desired, cooling air at ambient temperature can be supplied throughair inlet 148 into induced draft fan 150, which receives exhaust gasesfrom lines 152 (from burners 64) or 146 (from hot oil system 140).Temperature indicating controller 156 is located downstream of induceddraft fan 150 for controlling the outlet temperature of the exhaustgases. Exhaust gases are fed to conventional exhaust gas stack 160,which may be steel or equivalent. Exhaust gases exit to atmosphere at atemperature of approximately 600° F. through exhaust 162. As discussedabove, sample line 164 can feed into continuous emissions monitoringsystem 120 for monitoring of the exhaust gases.

Some or all of the burner exhaust from burner exhaust line 178 is fed tosweep gas line 180, which pulls off the burner exhaust before air isadded. This maintains a less than 5% oxygen content, in order tosuppress combustion. (Typically, 3% oxygen content equals nocombustion.) Alternatively, the sweep gas can be pulled from hot oilheater exhaust line 146 through line 181 when oxygen content isappropriate and/or when lower sweep gas temperatures are appropriate.Sweep gas in line 180 is fed by sweep gas blower 182 to sweep gas header184, which supplies sweep gas to hot oil screw dryer 40 through line 46and to indirect fired rotary calciner desorber 60 through inlet line 66and to the desorber seals through line 68, as discussed above.

FIG. 2 schematically illustrates a process and apparatus substantiallysimilar to those shown in FIG. 1, but using nitrogen in the sweep gas.The remaining components in FIG. 2 are substantially similar to thosediscussed above with respect to FIG. 1. That discussion will not berepeated herein.

Although FIG. 2 shows nitrogen for use as the sweep gas, one havingordinary skill in the art recognizes that other inert gases could beused, like CO₂ or argon. Accordingly, the invention is not limited tothe use of nitrogen.

The system in FIG. 2 includes liquid nitrogen storage tanks 200. Two tofour 1,000 to 20,000 gallon tanks may be utilized, depending on need.Liquid nitrogen storage tanks 200 feed liquid nitrogen through nitrogeninlet line 201 to nitrogen vaporizers 202. Nitrogen vaporizers 202 areheat exchangers which convert the liquid nitrogen to gas. Nitrogenvaporizers 202 receive hot gases from hot gas inlet line 203, whichreceives hot gases from hot oil system 240 through line 206, which iscontrolled by control damper 208. Exhaust gas from hot oil system 240 inexhaust gas line 206 has a temperature on the order of 700° F. to 1000°F. Exhaust gas in outlet line 205 from nitrogen vaporizers 202 has atemperature on the order of 300° F. to 600° F. Exhaust gas in exhaustgas line 205 can be recirculated through exhaust gas line 203 or sent tostack 260 through exhaust gas line 207. The vaporized nitrogen is fedfrom header 204 to sweep gas inlet 246 for hot oil screw dryer 240,inlet 266 for indirect fired rotary calciner desorber 260 and inlet 267,which provides seal gas, in the manner discussed above in FIG. 1.

FIG. 2 also shows exhaust gas being withdrawn from hot oil screw dryer240 through exhaust gas line 250 and exhaust gas being withdrawn fromindirect fired rotary calciner desorber 260 through exhaust gas line270. Exhaust gas in line 250 and exhaust gas in line 270 will bediscussed in more detail below with respect to FIGS. 3 and 4,respectively.

FIG. 3 schematically illustrates a process and apparatus useful forrecovering and treating hazardous and non-hazardous components from aprocess stream generated from the indirect heated hot oil screw dryer 40or 240, shown in FIGS. 1 or 2, respectively.

By way of example, exhaust gas from exhaust gas line 50 or 250 is fed atabout 11,450 pounds per hour with about 10,400 pounds per hour beingwater, 156 pounds per hour being organics and four pounds per hour beingparticulates, at a temperature on the order of 210° F. to 250° F. towater spray quench device 310, in which water is atomized into the gasstream at a flow rate of about 12,500 pounds per hour (25 gpm). The gasstream is at a temperature of between 100 to 150° F. Water spray quench310 is available from Turbotak, for example. In water spray quench 310,particulates and condensed exhaust gases drop out with the waterdroplets. Water supply line 312 controlled by control valve 311 feedswater at a flow rate of about 12,500 pounds per hour at about 100° F. to150° F. and at a pressure of approximately 100 to 150 psi to obtain gooddroplet size definition. Quenched gas outlet 314 feeds quenched gas tocondenser 320, which condenses out water and organics. Condenser 320 ison the order of 12 MM BTUH in the form of a shell and tube heatexchanger having condenser coils 326. These condenser coils may besupplied by Doyle and Roth.

Cooling water is supplied to condenser coils 326 through cooling waterinlet 321 at a temperature of from ambient to about 100° F. Coolingwater (warmed) exits condenser coils from cooling water outlet 325.Cooling water inlet 321 is controlled by control valve 322 and atemperature indicating controller 323 that senses the temperature of thevent gas in vent gas outlet 324, which is at about 100° F. to 150° F.with a flow rate of about 3600 pounds per hour (2630 pounds per hourwater, 80 pounds per hour organics and 1.2 pounds per hourparticulates). Vent gas from vent gas outlet 324 may be supplied to ventgas inlet 100 or 200 as shown in FIGS. 1 or 2, respectively.

Condensed liquid is drawn from condenser 320 through condensed liquidoutlet 327. This condensed liquid is mostly water at a temperature ofbetween 50° F. and 150° F. and has a flow rate of about 20,350 poundsper hour. This condensed liquid is fed to oil/water separator 330 thatcomprises a 5,000 gallon tank with baffles. Oil/water separator may besupplied by Great Lakes Environmental. Lighter oils from oil/waterseparator 330 are withdrawn through outlet 332 at about 78 pounds perhour at about 50° F. to 150° F. As used herein, "lighter oils" are thoseoils that are lighter than water and may include those conventionallyknown as BTEX (benzene, toluene, ethylene and xylene) compounds. TheseBTEX compounds may be put back into the oil in storage tank 470discussed below with respect to FIG. 4 in order to reduce the viscosityand make the oil more flowable. The lighter oils in outlet 332 are at atemperature of about ambient plus 10 or 20° F., depending on flow rate.This flow rate is controlled by control valve 333. The lighter oils aresent to portable containers 335. These portable containers may simply be50 gallon drums or tanks or 1,000 gallon tanks on farm wagons, forexample.

Level switch 336 controls the level in the oil/water separator 330.Condensed water is withdrawn from oil/water separator 330 throughcondensed through condensed water outlet 338 at about 50° F. to 150° F.and a flow rate of about 20,350 pounds per hour. This condensed water isfed to low pressure pump 344 through inlet 340 and/or high pressure pump348 through inlet 342. Low pressure pump 344 operates at approximately30 psi, while high pressure pump 348 operates at approximately 150 psi.Low pressure pump outlet 346 and high pressure pump outlet 350 feedwater to bag filters 352. Separate bag filter sets are provided in bagfilters 352 for each pump because of the pressure differential. Forexample, two filter banks of six filters each may be provided for eachoutlet, with three of these being on-line and three being off-line. Bagfilters 352 typically comprise felt filters, which are disposable. Wetsolids including filter bags are withdrawn from bag filters 352 throughline 354 and are sent to holding tank 356 for solids to be recycled.These solids in holding tank 356 may be returned, filter bags and all,to material feed 10 shown in FIG. 1, for example.

Bag filters 352 also include water outlet 358, the flow of which iscontrolled at about 7850 pounds per hour at about 50° F. to 150° F. bycontrol valve 360 for feed into clay anthracite adsorbent (CAA) filters362. These filters adsorb "large" (on the order of 10 μm) oil droplets.CAA filters 362 may be supplied by Great Lakes Environmental. Filterwater exits CAA filters 362 through filtered water line 364 which iscontrolled by control valve 366 for feed to carbon adsorber 368.

Carbon adsorber 368 also can be supplied by Great Lakes Environmentaland utilizes granulated activated carbon. Carbon adsorber 368 adsorbsdissolved organics that are finely dispersed or solubilized in water,e.g., alcohols and dissolved BTEX compounds. Treated water transfer line370 withdraws treated water from carbon adsorber 368 for feed to treatedwater storage tank 374. Analyzing controller 372 checks for replacementof the carbon units by monitoring an appropriate parameter orparameters, such as total organic carbon content. Treated water storagetank 374 may be merely a 20,000 gallon polypropylene tank or afractionator, i.e., a sloped bottom, transportable truck trailer tank.

The water level in treated water storage tank 374 is monitored by levelindicator 376. When desired or necessary, water can be withdrawn fromtreated water storage tank 374 through transfer water line 378 bytreated water transfer pumps 380, which are on the order of 50 gpm.Treated water in treated water outlet 390 is sent to a header (notshown) to be sent to a cooling tower (not shown), soil moisturizer 76shown in FIG. 1, through line 80, or to discharge.

FIG. 4 schematically illustrates a process and apparatus useful forrecovering and treating hazardous and non-hazardous components from aprocess stream generated from the indirect fired rotary calcinerdesorber 60 or 260 shown in FIG. 1 or FIG. 2, for example.

By way of example, exhaust gas in exhaust gas line 70 or 270 is fed tooil spray quench 410 at a temperature on the order of 800° F. to 1200°F. at about 7775 pounds per hour with about 2965 pounds per hour beingorganics and 1925 pounds per hour being particulates and the remainderbeing sweep gas. Oil spray quench 410 could be a quench elbow thatincludes a pipe with spray nozzles angled down into the sump of absorber416. Oil spray quench 410 includes quench spray inlet 412 for oil at atemperature of approximately 250° F. and a flow rate of about 29,950pounds per hour and an exhaust stream outlet 414 at approximately 350°F. Exhaust stream 414 includes exhaust gas and oil in a condensed,quenched stream having liquid and gaseous components. Exhaust stream 414feeds exhaust gas to absorber stripper tray tower 416, which isavailable from Glitsch Technologies, for example. Absorber 416 includesstripper trays 418 for stripping out heavy oils, such as asphaltenes,pyridines and pyrenes. Exhaust gas is withdrawn in separated gas stream420 at about 3500 pounds per hour and a temperature of about 250° F.This exhaust gas is primarily lower boiling point organics (583 poundsper hour) with some residual water and particulates (29 pounds perhour), at a temperature on the order of 250° F. This temperature will bevery close to the control temperature and can be varied as desired.

The exhaust gas in separated gas stream 420 is sent to absorbercondenser 422, a shell and tube heat exchanger, for condensing out lowerboiling point compounds and residual water. It should be noted that thiscondenser should be made easy to clean, because of the composition ofthe compounds in the feed stream. Cooling water inlet 426 feeds coolingwater at about 50° F. to 100° F. Cooling water outlet 424 withdrawswater from condenser 422 at a temperature about 50° F. to 120° F.Absorber condenser 422 includes condenser coils 427. Condenser vent gasoutlet 428 exhausts separated gases. Temperature indicating controller429 controls the cooling water flow rate, as desired. Condensed liquidoutlet 421 withdraws condensed liquid at about 50° F. to 120° F. to besent to oil/water separator 430, which is designed for both lighter andheavier than water materials. Oil/water separator 430 may be supplied byGreat Lakes Environmental. Oil/water separator 430 includes separatedwater outlet 432 withdrawn at a flow rate of about 228 pounds per hourand a temperature of about 50° F. to 120° F. by residual water pump 433,sized as necessary (on the order of 10 to 50 gpm). Residual water 434can be sent to oil/water separator 330 shown in FIG. 3 for furthertreatment. Water level indicating controller 435 controls the liquidlevel in oil/water separator 430.

Screw conveyor outlet 436, driven by drive motor 438, is designed forforcing out sludges and heavy oils from oil/water separator 430. Lightoils are drawn from oil/water separator 430 through light oil exhaustline 440 and are fed into screw conveyor 436. A level indicatingcontroller 442 monitors the level of the sludges and heavy oils in screwconveyor 436.

Recovered heavy oil product is withdrawn from screw conveyor 436 inrecovered heavy oil product line 446.

Some oil product may be drawn off from absorber 416 by product return448 when indicated as being necessary by level indicating controller andcontrol valve combination 447. This product in product return 448 can becombined with recovered heavy oil product in line 446 to be sent tostorage in line 449. Product storage pumps 450 pump recovered heavy oilproduct from line 449 to line 452 into product cooler 454. In someapplications, product cooler 454 may not be necessary. Nevertheless,when used, product cooler 454 cools the product from about 120° F. downto any necessary temperature. Product cooler 454 includes cooling waterinlet 458, the flow of which is controlled by temperature indicatingcontroller 460 and control valve to provide cooling water to productcooler 454. cooling water outlet 456 returns cooling water to thecooling water loop or to a cooling tower, for example.

Cooled product is withdrawn from product cooler 454 through cooledproduct outlet 462 at a flow rate of about 1.3 gpm and into productstorage tank 470. Product storage tank 470 may be equivalent to treatedwater storage tank 374 discussed above with respect to FIG. 3. However,product storage tank 470 includes an electric tank heater 471 that ispowered by electric power source 472 controlled by temperature indicator474. Product storage tank 470 also includes a level indicator (e.g.,sight glass) 475. A control valve, such as a manual control valve 476,is provided for withdrawing product from product storage tank 470.Product transfer pump 478 withdraws product at a flow rate ofapproximately 10 to 50 gpm to be sent to oil product load line 479 to beloaded into tanker trucks, for example.

Product storage tank 470 also includes a condensing vent 468 (e.g., anair vent) that condenses any residual VOCs, for example, back to aliquid. Condensing vent 468 is available from Graham Manufacturing.

If required, absorber 416 can be provided with a solvent supply systemdiscussed below. Solvent supply tank 480 contains, as is known in theindustry, light cycle oil (high aromatics content), or other appropriatesolvent such as hexane or toluene, or recycled BTEX compounds recoveredfrom the dryer exhaust stream 50/250 and recycled from the downstreamabsorber condenser. Solvent supply tank 480 includes a condensing vent482, similar to condensing vent 468 discussed above.

Solvent supply tank 480 includes solvent supply line 484 (at about 200°F. and a flow rate of about 9.5 gpm) and solvent supply pump 486 forfeeding solvents to absorber 416 through recycle flow (reflux) line 492.The solvents are used to strip organics out, if necessary. Flowindicating controller and valve 488 control flow of solvent to absorber488.

Absorber 416 also includes separated liquid stream 494, which includesstripped liquid organics taken out by stripper trays 418. Liquid stream494 has a temperature of about 350° F. and a flow rate of about 2370pounds per hour with about 1895 pounds per hour of particulates.Combined liquid stream line 498 includes liquid from separated liquidstream line 494 and liquid from return line 496. Liquid in combinedliquid stream 498 is sent to absorber recycle pumps 500, which pumpliquid to auto backflush filters 502. These filters are available fromKrystal Klear or Rosemont. Auto backflush filters 502 are typicallystainless steel filters that are periodically and automatically purged,due to the heavy particulates which they separate. Filtered liquidoutlet recycle line 504 returns filtered liquid to absorber 416.Absorber recycle cooler 506 is sized at about 2 MM BTUH and cools theliquid in filtered liquid outlet recycle line 504 to about 250° F.Absorber recycle cooler 506 includes cooling water inlet 510 controlledby temperature indicating controller 512 to maintain about 250° F. andcooling water outlet 508. As discussed above, this cooled liquid can bereturned to absorber 416 through reflux line 492 or sent through supplyline 448 to be mixed with recovered heavy oil product in line 446.Liquid in reflux line 492, having a temperature of about 200° F. to 350°F. and a flow rate of about 10 to 50 gpm, is controlled by flowindicating controller and control valve 490.

Auto backflush filters 502 include backflush line 514 controlled bytimer control valve 516, which sends backflush at about 11,450 poundsper hour and a temperature of about 200° F. to 350° F. to backflushsettling box 518. Backflush settling box 518 may be a 20 to 40 cubicyard roll off system. Backflush settling box 518 includes a solidseparate line 520, which provides solids to recycle 522. These solidsalso include residual oil and may be sent back to material feed 10discussed above with respect to FIG. 1. Liquids are drawn from backflushsettling box 518 by return line 496, which is controlled by controlvalve 497.

By such an arrangement, the present invention provides a system in whichall materials can be recycled within the system or disposed of in acontrolled manner. Thus, the present invention provides a recovery andrecycling process with decontamination of soil and sludges. In thissystem, organic (and, if desired, inorganic) components are recoveredand recycled in a useful process. Also, the separate gas stream systemssignificantly increase the recovery of particular components. In oneaspect, the hot oil screw dryer 40 drives off water and other organicsthat separate easily in the oil/water separator. Also, the indirectfired rotary calciner desorber 60 drives off higher boiling compounds.In particular, the desorber has an increased effectiveness in pyrolizingdue to the absence of water and the elevated temperature of the materialentering the rotary desorber, which allows the system to achievepyrolysis temperatures much quicker. In this exhaust gas system, exhaustgases and heavy organics are readily separated in a stripping towerwithout the addition of water. Also, the separated heavy organics aresimilar to heavy crude oil and can be used as a feedstock for arefinery, for example.

While the present invention has been described with respect to what iscurrently considered to be the preferred embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. To the contrary, the invention is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims. The scope of the following claims is to beaccorded the broadest interpretation so as to encompass all suchmodifications and equivalent structures and functions.

What is claimed is:
 1. A process for recovering and treating hazardousand non-hazardous components from process streams generated from acontinuous system for selectively separating organic and inorganicconstituents from contaminated material, said process comprising:(a)heating, in a dryer, the contaminated material to a first temperaturesufficient to volatilize water and lower boiling point constituentscontained in the material, thereby producing a dried solid material anda first gas containing water vapor and volatilized lower boiling pointconstituents; (b) separating the first gas from the dried solidmaterial; (c) recovering the lower boiling point constituents from thefirst gas; (d) heating, in a desorber, the dried solid material to asecond temperature sufficient to volatilize higher boiling pointconstituents contained in the dried material, thereby producing asubstantially decontaminated solid material and a second gas containingvolatilized higher boiling point constituents; (e) separating the secondgas from the substantially decontaminated solid material; (f) recoveringthe higher boiling point constituents from the second gas; (g) heatingthe desorber with natural gas fired burners; (h) exhausting combustionproducts from the natural gas fired burners; and (i) feeding theexhausted combustion products in step (h) as sweep gas to at least oneof (1) the dryer to assist in heating the contaminated material in step(a), and (2) the desorber to assist in heating the dried solid materialand maintaining an appropriate partial pressure to effectively desorbcontaminants in step (d).
 2. A process according to claim 1, wherein thematerial in step (a) is treated in a dryer, which comprises an indirectheated hot oil screw dryer having a screw for conveying the material. 3.A process according to claim 2, further comprising heating hot oil in ahot oil system and feeding the heated hot oil to the screw to indirectlyheat the contaminated solid material fed to the dryer.
 4. A processaccording to claim 3, wherein the desorber in step (d) comprises anindirect fired rotary calciner desorber, and further comprisingexhausting combustion products from the natural gas fired burners to thehot oil system to assist in heating the oil.
 5. A process according toclaim 1, wherein the desorber comprises an indirect fired rotarycalciner desorber.
 6. A process according to claim 1, further comprisingfeeding the first gas to a water spray quench and condenser arrangementand separating the first gas into dryer vent gas and condenser/waterspray quench condensed liquid.
 7. A process according to claim 6,wherein the dried material in step (d) is heated in a desorber heatedwith natural gas fired burners and feeding the dryer vent gas to atleast one of (i) the natural gas fired burners as supplemental fuel and(ii) carbon adsorbers for adsorbing organics from the dryer vent gas. 8.A process according to claim 6, further comprising feeding the condensedliquid to an oil/water separator for separating the condensed liquidinto oils lighter than water and separated liquids.
 9. A processaccording to claim 8, wherein the lighter oils include those selectedfrom the group consisting of benzene, toluene, ethylene and xylene. 10.A process according to claim 8, further comprising filtering theseparated liquids to separate out solids and liquids.
 11. A processaccording to claim 10, further comprising returning the solids to thecontaminated material heated in step (a).
 12. A process according toclaim 10, further comprising recycling a portion of the separatedliquids to the water spray quench and condenser arrangement and sendinga portion of the separated liquids to clay anthracite and carbonadsorbers for separating organics from the portion of the separatedliquid to produce treated water.
 13. A process according to claim 10,further comprising moisturizing the substantially decontaminated solidmaterial separated in step (e), withdrawn from the desorber using thetreated water.
 14. A process according to claim 1, wherein step (f)comprises feeding the second gas in step (e) to an oil spray quench andgenerating a quenched stream.
 15. A process according to claim 14,further comprising feeding the quenched stream to an absorber andseparating the quenched stream into (i) a separated gas streamcomprising primarily lower boiling point organics together with residualwater and (ii) a condensed liquid outlet.
 16. A process according toclaim 15, further comprising feeding the separated gas stream to anabsorber condenser for condensing the separated gas stream into acondensed stream.
 17. A process according to claim 16, furthercomprising feeding the condensed stream to an oil/water separator,separating the condensed stream into water and heavy oils andwithdrawing lighter oils from the oil/water separator.
 18. A processaccording to claim 17, further comprising separately withdrawing theheavy oils, the lighter oils and the water from the oil/water separator.19. A process according to claim 18, further comprising feeding thewater to an oil/water separator used in separating oils and wateremanating from a system for treating the first gas separated in step(b).
 20. A process according to claim 18, further comprising adding thelighter oils to the heavy oils to form a product oil stream withdrawnfrom the oil/water separator.
 21. A process according to claim 20,further comprising feeding the condensed liquid outlet to backflushfilters, generating a filtered liquid outlet and feeding a portion ofthe filtered liquid outlet to the product oil stream.
 22. A processaccording to claim 18, further comprising feeding the product oil streamto a heated storage tank.
 23. A process according to claim 15, furthercomprising feeding the condensed liquid outlet to backflush filters andgenerating a filtered liquid outlet and a settling liquid outlet.
 24. Aprocess according to claim 23, further comprising feeding the filteredliquid back to the absorber in a reflux line.
 25. A process according toclaim 24, further comprising feeding a solvent to the reflux line toassist in the separation in the absorber.
 26. A process according toclaim 23, further comprising feeding a portion of the filtered liquidoutlet to the oil spray quench.
 27. A process according to claim 1,wherein step (i) comprises feeding the exhausted combustion products instep (h) as sweep gas only to the dryer to assist in heating thecontaminated material in step (a).
 28. A process according to claim 1,wherein step (i) comprises feeding the exhausted combustion products instep (h) as sweep gas only to the desorber to assist in heating thedried solid material and maintaining an appropriate partial pressure toeffectively desorb contaminants in step (d).
 29. A process according toclaim 1, wherein step (i) comprises feeding the exhausted combustionproducts in step (h) as sweep gas both to the dryer to assist in heatingthe contaminated material in step (a) and to the desorber to assist inheating the dried solid material and maintaining an appropriate partialpressure to effectively desorb contaminants in step (d).
 30. Anapparatus for recovering and treating hazardous and non-hazardouscomponents from process streams generated from a continuous system forselectively separating organic and inorganic constituents fromcontaminated material, said apparatus comprising:a dryer for heating thecontaminated material to a first temperature sufficient to volatillizewater and lower boiling point constituents contained in the material,thereby producing a dried solid material and a first gas containingwater vapor and volatilized lower boiling point constituents; a firstseparation system for separating the first gas from the dried solidmaterial; a first recovery system for recovering the lower boiling pointconstituents from the first gas; a desorber for heating the dried solidmaterial to a second temperature sufficient to volatilize higher boilingpoint constituents contained in the dried material, thereby producing asubstantially decontaminated solid material and a second gas containingvolatilized higher boiling point constituents; a second separationsystem separating the second gas from the substantially decontaminatedsolid material; a second recovery system for recovering the higherboiling point constituents from the second gas; natural gas firedburners for heating the desorber; an exhaust line for exhaustingcombustion products from the natural gas fired burners; and a feedsystem for feeding the exhausted combustion products as sweep gas to atleast one of (i) the dryer to assist in heating the material, and (ii)the desorber to assist in heating the dried solid material andmaintaining an appropriate partial pressure to effectively desorbcontaminants.
 31. An apparatus according to claim 30, wherein the dryercomprises an indirect heated hot oil screw dryer having a screw forconveying material.
 32. An apparatus according to claim 31, furthercomprising a heater for heating the hot oil in a hot oil system and afeed system for feeding the heated hot oil to the screw to indirectlyheat the contaminated material heated in the dryer.
 33. An apparatusaccording to claim 31, wherein the desorber comprises an indirect firedrotary calciner desorber, and further comprising an exhaust line forexhausting combustion products from the natural gas fired burners to thehot oil system to assist in heating the oil.
 34. An apparatus accordingto claim 30, wherein the desorber comprises an indirect fired rotarycalciner desorber.
 35. An apparatus according to claim 30, wherein saidfirst recovery system comprises a feed system for feeding the first gasfrom the dryer to a water spray quench and condenser arrangement and aseparator for separating the first gas into dryer vent gas andcondenser/water spray quench condensed liquid.
 36. An apparatusaccording to claim 35, further comprising a vent gas feed for feedingthe dryer vent gas to at least one of (i) the natural gas fired burnersas supplemental fuel and (ii) carbon adsorbers for adsorbing organicsfrom the dryer vent gas.
 37. An apparatus according to claim 35, furthercomprising a condensed liquid feed for feeding the condensed liquid toan oil/water separator for separating the condensed liquid into oilslighter than water and separated liquids.
 38. An apparatus according toclaim 37, wherein the lighter oils include those selected from the groupconsisting of benzene, toluene, ethylene and xylene.
 39. An apparatusaccording to claim 37, further comprising a filter for filtering theseparated liquids to separate out solids and liquids.
 40. An apparatusaccording to claim 39, further comprising a return line for returningthe solids to the contaminated solid material heated in the dryer. 41.An apparatus according to claim 39, further comprising a recyclingsystem for recycling a portion of the separated liquids to the waterspray quench and condenser arrangement and an organics separator forsending a portion of the separated liquids to clay anthracite and carbonadsorbers for separating organics from the portion of the separatedliquid to produce treated water.
 42. An apparatus according to claim 39,further comprising a moisturizer for moisturizing the substantiallydecontaminated solid material withdrawn from the desorber using thetreated water.
 43. An apparatus according to claim 30, wherein saidsecond recovery system comprises a feed system for feeding the secondgas from the desorber to an oil spray quench that generates a quenchedstream.
 44. An apparatus according to claim 43, further comprising aquenched stream feed for feeding the quenched stream to an absorber anda separator for separating the quenched stream into (i) a separated gasstream comprising primarily lower boiling point organics together withresidual water and (ii) a condensed liquid outlet.
 45. An apparatusaccording to claim 44, further comprising a separated gas stream feedfor feeding the separated gas stream to an absorber condenser forcondensing the separated gas stream into a condensed stream.
 46. Anapparatus according to claim 45, further comprising a condensed streamfeed for feeding the condensed stream to an oil/water separator, whichseparates the condensed stream into water and heavy oils, and adischarge line for withdrawing lighter oils from the oil/waterseparator.
 47. An apparatus according to claim 46, further comprisingseparate discharge lines for separately withdrawing the heavy oils, thelighter oils and the water, from the oil/water separator.
 48. Anapparatus according to claim 47, further comprising a water feed forfeeding the water to an oil/water separator used in separating oils andwater emanating from the first recovery system.
 49. An apparatusaccording to claim 47, further comprising a line for adding the lighteroils to the heavy oils to form a product oil stream withdrawn from theoil/water separator.
 50. An apparatus according to claim 49, furthercomprising a condensed liquid outlet for feeding the condensed liquidoutlet to backflush filters that generate a filtered liquid, and afiltered liquid outlet for feeding a portion of the filtered liquidoutlet to the product oil stream.
 51. An apparatus according to claim52, further comprising a tank feed line for feeding the product oilstream to a heated storage tank.
 52. An apparatus according to claim 49,further comprising a condensed liquid outlet feed for feeding thecondensed liquid outlet to backflush filters that generate a filteredliquid outlet and a settling liquid outlet.
 53. An apparatus accordingto claim 52, further comprising a filtered liquid feed for feeding thefiltered liquid back to the absorber in a reflux line.
 54. An apparatusaccording to claim 53, further comprising a solvent feed for feeding asolvent to the reflux line to assist in the separation in the absorber.55. An apparatus according to claim 52, further comprising a filteredliquid feed for feeding a portion of the filtered liquid outlet to theoil spray quench.
 56. An apparatus according to claim 30, wherein saidfeed system feeds the exhausted combustion products as sweep gas only tothe dryer to assist in heating the contaminated material.
 57. Anapparatus according to claim 30, wherein said feed system feeds theexhausted combustion products as sweep gas only to the desorber toassist in heating the dried solid material and maintaining anappropriate partial pressure to effectively desorb contaminants.
 58. Anapparatus according to claim 30, wherein said feed system feeds theexhausted combustion products as sweep gas both to the dryer to assistin heating the contaminated material and to the desorber to assist inheating the dried solid material and maintaining an appropriate partialpressure to effectively desorb contaminants.